Which is a secondary source about the civil war? gettysburg address movie about gettysburg union soldiers' personal letters

Movie about Gettysburg

Explanation:

Primary sources are those that provide a first-hand account of a particular event or time period. These are particularly important to researchers because they provide information that is original and as close to the event as possible. On the other hand, secondary sources are those that interpret, synthesize or analyze primary sources. In this example, the Gettysburg Address would be considered a primary source, while a movie about this would be considered a secondary source, as it examines a primary one.

8 - (2a + 7) = a + 40     distribute/multiply - into (2a + 7)

8 - 2a - 7 = a + 40

1 - 2a = a + 40       add 2a on both sides

1 = 3a + 40         subtract 40 on both sides

-39 = 3a       divide 3 on both sides

-13 = a

[proof]

8 - (2a + 7) = a + 40

8 - (2(-13) + 7) = -13 + 40

8 - (-26 + 7) = 27

8 - (-19) = 27

8 + 19 = 27

27 = 27